An adoptive mother, accused of torturing and murdering her 12-year-old daughter, is now on trial.

Madera county prosecutors revealed Friday that they're leaning towards pursuing the death penalty against 42-Year old Amy Chavoya.

The victim's brother is the source of a lot of the evidence against Chavoya. He just told a judge she used a stun gun and brute force to beat him and some siblings. Prosecutors say the abuse eventually killed his sister.

Mariah Flores suffered before her death, there's no doubt about that. The forensic pathologist who examined her found bruises and scars all over her body. Dr. Mark Super said "first of all, you don't expect to see 12-year-olds dead in your morgue very often and when you do see them, all those scars and bruises is unusual.

Mariah's brother says abuse was common in the house and he and Mariah took the brunt of it from their adopted mother, Amy Chavoya. He says they were sometimes forced to sleep outside, they were sometimes starved, and Amy sometimes used a stun gun on them as punishment.

He still has the scars to prove it. "Are you saying those are taser marks," a prosecutor asked. "Who put them on you?" The Mariah's brother replied: "Amy."

Chavoya's defense attorney says there's evidence the girl inflicted some injuries on herself. And Mariah had a fall in the shower shortly before she died that could explain other injuries.

But prosecutors say the evidence of abuse leading to murder is clear and they may seek the ultimate punishment. "I am treating this as a death penalty case at this point in time, Madera County District Attorney David Linn said.